You may have noticed when picking colors, or using them, that there are a variety of dots and marks before and after some cross stitch numbers. These are those marks if you’re unsure what we mean:DMC threads with dots after numbers
Thanks to the new DMC color chart that came out thanks to the 35 new DMC threads, DMC make more of these dots, and if you have a keen eye, you’ll notice the pre-2018 color card has different dots to the pre-2018 color card.

So what are they? Basically, they’re changes in formula to avoid using nasty chemicals. In the EU dye usage is highly monitored and as a result they’ve required suppliers of threads to make sure they use only friendly dyes. This has happened in two stages; firstly in 1994 when a lot of greys were changed to fit in with new laws, and again in late 2017 when lots of the reds were affected.

Well that’s interesting, but why do I care?

I’m glad you asked. Dye lots. And its actually quite a problem. You see, they couldn’t just change the color fomulation and keep the colors perfect, and as a result we now need to monitor which version of the threads we’re using; old or new. An example of how different they can be is below on some of the 1994 color changes:DMC 3861 dye lot differences (source: Cindi Csraze)
In fact, DMC even carry the warning on their color charts:

Do not mix with the original colours without the dot.

That’s just how serious this problem might be, so from now on, keep your eye out for those dots of colors 304, 321, 498, 815 and 816.

My thanks to DMC and Sidar who supplied information, along with Martha Beth.